Vitamins are one of the most important nutrients that keep the human body healthy. However, too much of anything is good for nothing. Consuming more than the recommended amount of a certain vitamin can lead to several complications.

Therefore, it is very important to identify the symptoms and causes of vitamin toxicity. Continue reading this article to know more about this condition.

Vitamin toxicity or hypervitaminosis is an abnormal condition that arises due to high vitamin levels in the body. There are two types of vitamins, namely, water-soluble and fat-soluble vitamins. These fat-soluble vitamins are not easily cleared out from the human body, increasing the risks of vitamin toxicity.

Vitamin A, B3, B6, C, D and E are the primary causes of vitamin toxicity. Consuming excessive amounts of animal food sources such as fish oil or liver and supplements with high content of preformed vitamin A cause hypervitaminosis A. Individuals who intake more than the prescribed limit of vitamin B3 or use it for a long time have higher chances of having vitamin B3 toxicity. Foods like poultry products, pork, whole grains, fish, blueberries, legumes and high doses of vitamin B6 supplements can cause hypervitaminosis B6. Furthermore, excessive dosage of vitamin C leads to toxicity. People taking a dosage of 100 mcg or more vitamin D supplements are at risk of vitamin D toxicity.

The symptoms of vitamin toxicity are as follows – 

• Frequent and cloudy urination
• Irritation of the eyes 
• Increase in sensitivity to light 
• Rapid or irregular heartbeat 
• Joint and bone pain 
• Muscle pain 
• Mood changes and confusion 
• Convulsions
• Fatigue
• Headache 
• Flushing of the skin
• Disturbance in the skin
• Changes in hair texture
• Loss of appetite 
• Constipation 
• Vomiting and nausea
• Diarrhoea 
• Moderate weight loss

Vitamin toxicity has several side effects. These include intracranial hypertension, vision changes, nausea, dizziness, migraines, bone ache, coma and even death, in some severe cases. Prolonged use of vitamin B3 causes liver damage, especially in people with existing liver disease. 

Excessive use of vitamin B6 causes loss of coordination, disrupted digestion, and skin lesions. Furthermore, high doses of vitamin D is linked to heart problems, cancer risk and bone fractures. 

Vitamin E overdose increases the odds of prostate cancer (in men), haemorrhages and stroke.

People taking a hundred thousand IUs (International Units) of vitamin A have a high chance of getting vitamin A toxicity. Children and babies are comparatively more sensitive to vitamins. 

They might become ill after consuming smaller amounts of the nutrient. Moreover, individuals with liver diseases are at a higher risk of getting affected by vitamin B3 toxicity.

A medical professional might recommend you to do one of the following tests to diagnose vitamin toxicity – 

• Skeletal radiography
• Hand radiography 
• Helical CT scanning and urography
• CT scan of the brain 
• KUB (kidney, ureters, bladder) film
• Bone mineral density test
• Electrocardiography

Treatment for vitamin toxicity is usually supportive and symptomatic. Gastrointestinal decontamination can be beneficial to reduce the amount of vitamin absorption. In case of acute overdoses, use charcoal to treat the issue. Antidiarrheals and antiemetics can be useful if needed. Individuals with severe symptoms of vitamin A toxicity might need medications such as mannitol and diuretics. Furthermore, patients with vitamin D toxicity and severe hypercalcemia might need hydration, steroids, diuretics, mithramycin or calcitonin to treat the condition. 

Nevertheless, avoid consuming more than the recommended amounts of vitamins in your diet and through supplements. This measure acts as prevention for vitamin toxicity. If the symptoms do not reduce after reducing the vitamin intake, consult your doctor to plan for the diagnosis and treatment.